Anne van Kesteren:
Also, I think the HTML specification should mandate (as SHOULD-
level requirement, probably) support for the various supported
image formats as it gives a clear indication of what authors can
rely on and what user agents have to implement in order to support
the web.
Which format would this be for animated true-colour images, lossy or
lossless? MNG/JNG, APNG, JS+PNG/JPEG, SVG+PNG/JPEG ...? Or is there
no need to require one? If so why not?
I am still not convinced (X)HTML5 should recommend support for
anything but itself. Although HTTP, CSS, JS, GIF and JPEG/JFIF might
seem safe, they all have certain (exotic) features that are not
implemented (the same / correctly / at all) in current browsers. I
think informative advise is all there needs to be, but RFC 2119 does
not have something between 'should' and 'may', like 'ought' and
'suggested' or 'advocated' perhaps.
--
RFC 2119:
'must' = 'shall' = 'required'
'must not' = 'shall not'
'should' = 'recommended'
'should not' = 'not recommended'
'may' = 'optional'
Terms not defined therein, but sometimes encountered in "Web
standards" are for example 'forbidden', 'mandatory', 'prescribed',
'compulsory', 'permissive', 'allowed', deprecated', 'obsolete',
'will', 'would'.
